<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>异步加载JS文档</title>	
	<script>
		function loadJS(){
			var scriptEle = document.createElement('script');
			scriptEle.src = 'scripts/common.js';
			document.head.appendChild(scriptEle);
		}
	</script>
</head>
<body>
	<input type="button" value="单击我,加载common.js文件" onclick="loadJS()">
</body>
</html>